Brucite was first described in 1824 and named for the discoverer, American mineralogist, Archibald Bruce (1777–1818). A fibrous variety of Brucite is called Nemalite. It occurs in fibers or laths, usually elongated along [1010], but sometimes [1120] crystalline directions.

When cement or concrete are exposed to non negligible concentration of Mg2+, e.g. when these materials are left in prolonged contact with sea water or brines, Mg(OH)2 precipitates under the high pH conditions prevailing in the cement porewater. The neoformation of brucite, an expansive material, induces mechanical stress in the hardened cement paste and is responsible for the formation of cracks and fissures in concrete.

The use of dolomite as aggregate in concrete can also cause the magnesian attack and should be avoided.